Primer for internal combustion engine



1956 A. o. PAYNE 3,281,129

PRIMER FOR INTERNAL COMBUSTION ENGINE Filed June 14, 1965 INVENTOR. 60165 0, F4

United States Patent 3,281,129 PREVIER FOR INTERNAL COMBUSTION ENGINEAmos 0. Payne, Dubuque, Iowa, assignor to Clinton Engines orporation,Maquoketa, Iowa, a corporation of Michigan Filed June 14, 1965, Ser. No.463,697 7 Claims. (Cl. 26134) This invention relates to a primer for aninternal combustion engine and more particularly to a non-floodingprimer for use in starting an engine having a carburetor provided with afloat bowl and a fuel nozzle leading to a fuel-air mixture passageway,in which the primer delivers atomized fuel through the fuel nozzle tothe mixture passageway or venturi.

The invention comprises a pneumatic air pumping bel lows or bulb whichis connected by a tube to an axial passage in the needle valve whichmeters the flow through the fuel nozzle during normal running of theengine. A small bleed orifice in the needle valve communicates with thefuel in the float bowl. The primer bellows is adapted to be depressed toeject an ignitable fuel-air mixture through the needle valve and fuelnozzle into the fuel-air mixture passageway in the carburetor. Theneedle valve and tube are slowly refilled from the fuel supply by way ofthe bleed orifice so that repeated actuation of the bellows injects onlya small quantity of atomized fuel into the carburetor so as to avoidflooding the engine.

The principal object of the invention is to provide a new and improvedprimer for use in starting an internal combustion engine.

Another object of the invention is to provide a manually operated primerfor atomizing a measured quantity of fuel into the induction system ofan internal combustion engine to assist in starting the engine.

A further object of the invention is to provide a primer for an internalcombustion engine as described which eliminates flooding of the enginedue to repeated priming during starting thereof.

Other and further objects of the invention will be apparent from thefollowing description and claims and may be understood by reference tothe accompanying drawing which by way of illustration shows a preferredembodiment of the invention and What I now consider to be the best modeof applying the principles thereof. Other embodiments of the inventionmay be used without departing from the scope of the present invention asset forth in the appended claims.

The single figure of the drawing is a sectional view of a carburetorwith a primer according to the invention.

In the drawing the carburetor 10 is generally of conventionalconstruction and includes a body casting 12 with a fuel-air mixturepassageway or venturi 14 which forms part of the induction systemleading to the engine combustion chamber. A float bowl 16 is secured tothe body 12 by means of plug 18 which is threaded into the cylindricalopening 19 in the downwardly extending tubular portion 20 of thecarburetor body. The fuel contained in the float bowl is maintained atlevel 22 by means of an annular float 2 secured to arm 26 which ispivoted about pin 28. Fuel inlet 30 leads to valve seat 32 containing afuel passageway 34. A valve member 36 rests on a portion 38 of arm 28 soas to control the flow of the fuel into the float bowl and maintain thefuel level 22.

A fuel nozzle 40 is mounted within the cylindrical opening 19 of theportion 20 of the carburetor and extends into the fuel-air mixturepassageway 14. An adjustable needle valve 42 is threadedly engagedwithin plug 18 and cooperates with the metering orifice 44 of the fuelnozzle 40 to control the normal flow of fuel through the 3,281,129Patented Oct. 25, 1966 nozzle. Fuel flows from the float bowl throughpassageway 46 into an annular chamber 48 and is drawn up therefromthrough nozzle 40 and into the venturi. The carburetor is provided witha conventional idling system 50 and passages associated therewith so asto allow the engine to idle.

The needle valve 42 is provided with an axial bore 66, one end of whichforms a primer jet 61, and a bleed orifice 62 which connects the axialbore 60 with the annular chamber 48. A radial bore 64 at the lower endof the axial bore 60 leads to an annular chamber 66. A tube 68 in theplug 18 connects priming tube 70 with the annular chamber 66. The otherend of the priming tube is secured to a pneumatic bellows or bulb 72which may be mounted on a structural member 74 located remote from theengine. The bellows 72 is provided with a vent opening 76 which allowsfor refill of the bellows following use thereof.

The fuel in the float bowl flows through bleed orifice 62, down axialbore 66, and through radial bore 64 so as to fill the annular chamber66, inlet tube 68, and priming tube 70 to the fuel level 22 maintainedin the float bowl. The flexible priming tube 70 is brought up past thelevel 22 and is adjusted relative to the carburetor so that the volumeof the fuel contained within the tube 70 is equal to the amount of airdisplaced by a single stroke of the bellows 72.

To prime the engine the operator places his finger over the belows vent76 and compresses the bellows so as to pressure the fuel in the tube 79and atomize and eject this fuel through passage 60 and nozzle 40 intothe mixture passageway 14 so as to provide a rich starting mixture.Following the initial priming of the engine, the belows is released andfuel will flow from the float bowl back through bleed orifice 62 andinto the needle valve and tube 70. However, this refilling of the tubewill occur very slowly since the bleed orifice is small in diameter.Repeated actuation of the bellows 72 does not eject a full measure offuel, but continues to deliver a small volume of atomized fuel into thecarburetor venturi. In this way the invention prevents flooding of thecarburetor during starting since the amount of fuel injected into thecarburetor on the first stroke of the bellows is measured and it isimpossible during starting to subsequently immediately inject an equallylarge amount of fuel into the barburetor so as to flood the engine. Alarge amount of air is also supplied to the carburetor during repeatedactuation of bulb 72 to insure that the fuel-air mixture will beignitable.

While I have illustrated and described a preferred embodiment of myinvention, it is understood that this is capable of modification, and Itherefore do not wish to be limited to the precise details set forth butdesire to avail myself of such changes and alterations as fall withinthe purview of the following claims.

I claim:

1. In a carburetor for an internal combustion engine provided with afloat bowl containing liquid fuel and a fuel-air mixture passage, aneedle valve, a primer for supplying a combustible starting mixture tothe mixture passage comprising passage means comunicating with saidmixture passage in said needle valve, a priming tube connected to oneend of said passage means, an air pumping means at the end of saidpriming tube and operable upon actuation thereof to discharge thecontents of said priming tube through said passage means into saidmixture passage, and a bleed orifice communicating said passage with thefuel in said float bowl and through which fuel is supp-lied to saidpassage means and said priming tube at a measured rate to preventcomplete filling of said priming tube immediately after actuation ofsaid air pumping means so as to supply a combustible fuel-air mixture tosaid mixture passage and prevent flooding of the engine upon repeatedactuation of said air pumping means.

2. A carburetor according to claim 1 wherein said priming tube extendsoutside the carburetor and upwardly above the fuel level in said floatbowl.

3. In a carburetor for an internal combustion engine provided with afloat bowl containing liquid fuel, a fuelair mixture passage, a fuelnozzle for conducting fuel from the float bowl to the mixture passageand a needle valve controlling the flow of fuel through the fuel nozzle;a primer for supplying a combustible starting mixture to the passagecomprising a passage in said needle valve, '21 priming tube connected atone end to said needle valve passage, an air pumping means at the otherend of said priming tube and operable upon actuation thereof todischarge the contents of said priming tube through said passage in saidneedle valve and into said fuel nozzle and said fuel-air mixturepassage, and a metering orifice communicating said passage in saidneedle valve With the fuel in said float bowl and through which fuel issupplied to said priming tube at a measured rate to prevent completefilling of said priming tube immediately after actuation of said airpumping means so as to supply a combustible fuelaair mixture to saidmixture passage and prevent flooding of the engine upon repeatedactuation of said air pumping means.

4. A carburetor according to claim 3 wherein said metering orifice is asmaller diameter than said passage in said needle valve.

5. A carburetor according to claim 4 wherein said air pumping meanscomprises a manually operable bellows and said priming tube extendsoutside said carburetor with said other end thereof and said bellowsdisposed above the fuel level in said float bowl.

6. In a carburetor of the type provided with a float bowl containingliquid fuel, a fuel-air mixture passage, a fuel nozzle for conductingfuel from the float bowl to the mixture passage and a needle valvecontrolling the flow of fuel through the fuel nozzle; a primer forsupplying a combustible starting mixture to the mixture passagecomprising an axial passage in said needle valve, a priming tubeconnected at one end to one end of said axial passage and extendingoutside the carburetor uppumping means at the other end of said primingtube and operable upon actuation thereto to discharge the contents ofsaid priming tube through said passage in said needle valve and intosaid fuel nozzle and said mixture passage, and :a bleed orificecommunicating said passage in said needle valve with the fuel in saidfloat bowl and through which fuel is supplied to said axial passage andsaid priming tube at a measured rate to prevent complete filling of saidpriming tube immediately after actuation of said air pumping means so asto supply a combustible fuel-air mixture to said mixture passage uponcontinued actuation of said air pumping means.

7. In a carburetor of the type provided with a supply of liquid fuel, afiuel air mixture passage, a fuel nozzle for conducting fuel from saidsupply to the mixture passage and a needle valve controlling the flow offuel through the fuel nozzle; :a primer for supplying a combustiblestarting mixture to the passage comprising an axial passage in saidneedle valve, a priming tube connected at one end to said axial passageand extending upwardly above the fuel level, an air pumping means at theother end of said priming tube and operable upon actuation thereof todischarge the contents of said priming tube through said passage in saidneedle valve and into said fuel nozzle and said mixture passage, and ableed orifice communicating said passage in said needle valve with thefuel supply and through which fuel is supplied to said axial passage andsaid priming tube at a measured rate such that subsequent repeatedactuation of said air pumping means supplies smaller quantities of acombustible mixture to said mixture passage than is supplied by theinitial actuation of said air pumping means.

References Cited by the Examiner UNITED STATES PATENTS 696,146 3/1902Riotte et al. 1,166,084 12/1915 Ryder. 1,809,507 6/1931 Oarter 26l-72 XR2,656,167 10/1953 Phillips 26172 XR 2,827,272 3/1958 Phillips 261-72 XRFOREIGN PATENTS 258,716 4/ 1928 Italy.

HARRY B. THORNTON, Primary Examiner. wandly above the level of fuel insaid float bowl, an air RONALD R. WEAVER, Assistant Examiner.

1. IN A CARBURETOR FOR AN INTERNAL COMBUSTION ENGINE PROVIDED WITH AFLOAT BOWL CONTAINING LIQUID FUEL AND A FUEL-AIR MIXTURE PASSAGE, ANEEDLE VALVE, A PRIMER FOR SUPPLYING A COMBUSTIBLE STARTING MIXTURE TOTHE MIXTURE PASSAGE COMPRISING PASSAGE MEANS COMMUNICATING WITH SAIDMIXTURE PASSAGE IN SAID NEEDLE VALVE, A PRIMING TUBE CONNECTED TO ONEEND OF SAID PASSAGE MEANS, AN AIR PUMPING MEANS AT THE END OF THEPRIMING TUBE AND OPERABLE UPON ACTUATION THEREOF TO DISCHARGE THECONTENTS OF SAID PRIMING TUBE THROUGH SAID PASSAGE MEANS INTO SAIDMIXTURE PASSAGE, AND A BLEED ORIFICE COMMUNICATING SAID PAS-